Child safety seats have been in use in the United States and other jurisdictions for some time. The purpose of a child safety seat is to provide a satisfactory restraining mechanism for small children in the vehicle. The child safety seats are held in place by the vehicle's seat belts.
However, modern safety belts which consist of a shoulder and a lap portion are designed for adults and do not effectively safely restrain small children or child safety seats. Simply put, today's safety belts, if left unmodified, will allow a child safety seat to be thrown forward several inches even if the safety belt is used. This sudden forward movement will cause serious neck and shoulder injuries to a young child.
Hence, there is a problem with holding child safety seats in place on the car seat with conventional seat belts. A full understanding of the problem can be obtained after consideration of the construction and design of modern seat belts.
Generally, seat belts include lap and shoulder portions. The shoulder portion is normally attached to an inertia locking wind-up reel disposed next to the vehicle door or window and the lap portion is generally attached to a fixed anchor on the vehicle floor. The shoulder and lap portions are connected together as a continuous belt at the seat belt buckle or latch plate. The female end of the buckle is also attached to the floor of the vehicle.
When the vehicle stops suddenly or involved in a head-on collision, the inertia locking wind-up reel grasps the shoulder portion of the seat belt after a limited amount of belt is released from the wind-up reel. The locked wheel prevents any additional slack in the belt from being released. A limited amount of belt is released in order to prevent chest injuries to adults and to make the safety belt easy and comfortable to wear for the adult passenger. Normal or gradual movements by the adult passenger will automatically release additional belt from the inertia locking wind-up reel. Only sudden or forceful movements will cause the wind-up reel to lock against the shoulder portion of the belt after a limited amount of slack is released.
However, while some slack needs to be released from the wind-up reel to prevent chest injuries to adults and for the general comfort of an adult passenger, this same amount of looseness or slack causes a serious safety problem for small children seated in child safety seats. Specifically, the release of as little as six to eight inches of slack in the belt will result in a jolting forward movement of the child safety seat which can cause the seat to move forward violently and stop suddenly during hard braking or a collision. Further, in addition to the sudden forward movement, the seat will pivot about the buckle which will impart a twisting force to the child. The result can be serious neck and shoulder injuries to the child, including whiplash. Due to the underdeveloped nature of a young child's neck and shoulder muscles, the injuries can be serious and long lasting.
Accordingly, to remove the possibility of any slack being released from the wind-up reel during a hard brake or collision situation, seat belt gripping devices have been developed which allow the parent to remove any slack from the lap portion of the seat belt and thereafter lock the lap and shoulder portions of the belt together at the buckle. These seat belt gripping devices effectively inactivate the shoulder portion of the belt and allows the child safety seat to be held in place between the seat belt buckle and the lap portion, both of which are securely anchored to the floor of the car.
While these seat belt gripping devices that had been provided are a substantial improvement over no device at all, the devices currently available are still not without substantial problems. Specifically, two current types of devices are available. The first type is a plate-like device with an upper slot, a lower slot and a middle finger. The shoulder and lap portions of the belt are inserted through the upper and lower slots and draped over the front surface of the middle finger portion. This plate-like device relies upon friction to hold the shoulder and lap portions of the belt together. The problem with this type of device is that it is inherently hard for the parent to feed the shoulder and lap portions of the belt through the upper and lower slots. Further, once the shoulder and lap portions of the belt are fed into the slots, adjustment of the clamp while on the belt is extremely difficult. It has been found that many parents do not bother readjusting the belt every time the child safety seat is put in the car which defeats the very purpose of the clamp if slack is present in the lap portion of the belt. Thus, while the plate-like clamp is relatively effective, it is so difficult to use that its safety benefits often go unrealized.
A second type of device includes upper and lower clamping members that simply clamp the shoulder and lap portion of the belt together. However, the only types of these clamps that are currently available include standard knobs or wing-nuts that hold the upper clamping member in position. Because the clamp is placed directly next to the child seat, the children have access to the wing-nut or knob and therefore are able to remove or loosen the clamp.
In summary, while seat belt gripping devices are available for use with child safety seats, all of the currently available seat belt gripping devices are problematic for at least two reasons. First, they are difficult and frustrating for the parents to use and are consequently often used improperly. Second, they are not child-proof and because of their proximity to the child sitting in a car seat, they are often tampered with by the child and rendered ineffective.
Thus, there is a need for a device for use with child safety seats that holds the lap and shoulder portions of the seat belt together and which is both easy-to-use and child-proof.